Protective helmet

ABSTRACT

The design is the shape and configuration of the protective helmet as shown in the drawings.

FIG. 1 is a left side view of a protective helmet showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a rear view thereof; and,

FIG. 5 is a top view thereof. 

We claim the ornamental design for a protective helmet, as shown and described. 